OLDWICK, N.J., April 02, 2024--AM Best has revised the outlooks to negative from stable and affirmed the Financial Strength Rating of A+ (Superior) and the Long-Term Issuer Credit Ratings of "aa-" (Superior) of Vermont Mutual Insurance Company and its fully reinsured subsidiary, Northern Security Insurance Company, Inc. and its fully reinsured affiliate, Granite Security Insurance Company (formerly Granite Mutual Insurance Company). These companies are domiciled in Montpelier, VT and are members